• Computers and Concrete
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• 제19권6호
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• pp.659-666
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• 2017

Based on the Arrhenius equations, several hydration exothermic models that precisely calculate the influence of concrete's self-temperature duration on its hydration exothermic rate have been presented. However, the models' convergence is difficult to achieve when applied to engineering projects, especially when the activation energy of the Arrhenius equation is precisely considered. Thus, the models' convergence performance should be improved. To solve this problem and apply the model to engineering projects, the relationship between fast iteration and proper expression forms of the adiabatic temperature rise, the coupling relationship between the pipe-cooling and hydration exothermic models, and the influence of concrete's self-temperature duration on its mechanical properties were studied. Based on these results, the rapid convergence of the hydration exothermic model and its coupling with pipe-cooling models were achieved. The calculation results for a particular engineering project show that the improved concrete hydration exothermic model and the corresponding mechanical model can be suitably applied to engineering projects.

• 대한기계학회논문집A
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• 제25권8호
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• pp.1173-1182
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• 2001

Recent noticeable advances of CNC machine tools have considerably improved productivity and precision in manufacturing processes. However, in the respect of productivity some defects still remain because selection of machining conditions entirely depends on the experiences of programmers. Usually, machining conditions such as feed rate and spindle speed have been selected conservatively by considering the worst cases, and it has brought the loss of machining efficiency. Thus, the improvement of cutting force controller has been done to regulate cutting force constantly and to maximize feedrate simultaneously in case that machining conditions change variously. In this study, sliding mode control with boundary layer is applied to milling process for cutting force regulation and in a commercial CNC machining center data transfer between PC and PMC (programmable machine controller) of CNC machine is done using a standard interface method. And in the cutting force measurement, an indirect cutting force measuring system using current signal of AC servo is adopted in order not to use high-priced equipment like tool dynamometer. The purpose of this study is to maximize the productivity in milling process, thus its results can be applied to cases such as rough cutting process.

• 농촌지도와개발
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• 제23권4호
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• pp.361-374
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• 2016

This study examined the regulation status on wastewater treatment in agro-food processing and a case study on effluent treatment m ethods was carried out to evaluate any change after the mitigation of regulation. First, in order to clarify the area of investigation, the definition of small-scale agro-processing facilities was reviewed through literature survey and local government ordinance. The current law were separately analyzed into four areas; effluent treatment facilities, development of agro-processing industries, land use and food processes equipment. The exclusion clauses on wastewater discharging facility in the enforcement regulation were defined in detail, which can be served in practice. Site survey, after the questionnaire survey of the person in charge of the local unit, was carried out. As the result, this survey confirmed the positive effects of the deregulation on promoting sewer system service in rural areas, introducing the new processing construction and so on. In addition, it was found that some matters to be considered to determine whether to introduce wastewater treatment plan for public food processing facilities.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.532-535
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• 2003

In this paper, a Pl controlled feedback closed-loop voltage regulation scheme of the three-phase squirrel cage rotor self-excited induction generator (SEIG) driven by a variable-speed prime mover (VSPM) such as a wind turbine is designed on the basis of the static VAR compensator (SVC) and discussed in experiment fer the promising stand-alone power independent conditioner. The simulation and experimental results of the three-phase SEIG with the simple SVC controller for its stabilized voltage regulation prove the practical effectiveness of the additional SVC control loop scheme including the PI controller with fast response characteristics and steady-sate performance improvement.

• KIEAE Journal
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• 제4권2호
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• pp.41-47
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• 2004

This study is to improve plan for the law and regulation systems on the perpendicular greening with containers to improve urban environment. The supports backed by laws and regulations are imperative for the activation of building greening. Although some local administrations in Korea try to lead perpendicular greening on building by means of Green Building certification system and so on, greening policies and managements are not pushed forward with consistency. Therefore building greening should be admitted to be a substitute green tract of land. The positive construction and management of greenzone should be accomplished as well. Devices, so to speak, which put greening under an obligation or authorize it as legal landscape area should be made rather than recommendations to make greenzone through current incentive systems. Positive perpendicular greening on building can be achieved by supplementing the law and regulation and incentive system about simplified planter. If planting and managing of simplified planter are continually entrusted to residents, even vertical landscapes will be affected by illegal diversion and negligence in result. Therefore, supports from governments and local administrations are needed.

• 한국통신학회논문지
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• 제33권7C호
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• pp.529-533
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• 2008

본 논문은 FTTH 도입에 대비하여 현행 국내 광가입자망 구축 공법 및 케이블 포설 등에 관련된 기술기준의 개정 사항 도출을 위하여 광케이블의 곡률 반경과 밴딩 횟수의 변화에 따른 광케이블 채널 손실 특성 및 이종 모드간 광케이블 접속 시 발생하는 채널 손실 특성을 시험 측정하였다. 곡률 반경 및 밴딩 횟수의 변화에 따른 시험 측정 결과 30mm의 현행 허용 곡률 반경 기준을 보다 완화하여도 채널 손실 기준을 만족하는 것으로 나타났으며, 이종 모드간 케이블 접속 시험 측정에서는 다중 모드로부터 단일모드로의 접속 시 원활한 정보 전달이 불가능 한 것으로 나타나 향후 이종 모드간 광케이블 접속 규격에 대한 보다 심도 있는 연구가 요구되고 있다.

• 한국안전학회지
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• 제31권3호
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• pp.102-108
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• 2016

As a range of accidents happen frequently in our society due to safety insensitivity, researches on individual psychological characteristics related to safety behavior and on safety education are increasing. However, safety behavior research that targets university students as potential employees remains rare. Therefore, this research investigates individual characteristics and psychological factors that affect safety behaviors of university students. Research participants were 131 university students (80 males, 51 females) from the Gyeonggi-do and Chungnam areas. Psychological characteristics (self-regulation, cognitive failure, conscientiousness, and emotional stability) were included as variables that may predict university students' safety behaviors (habits, compliance, mistakes, and violations). The major findings of the study are as follows. Stepwise regression analysis showed conscientiousness was a major predictor explaining safety habits and safety compliance; Cognitive failure and emotional stability were main predictors explaining safety mistakes, and self-regulation was a major predictor explaining safety violations. These findings suggest that development of proper education programs focusing on individual characteristics would allow systematic improvement of safety behaviors of university students.

• 자원ㆍ환경경제연구
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• 제11권2호
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• pp.233-260
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• 2002

This paper tries to analyze the efficiency structure and regulatory effects in electric power industry by using total factor productivity and indices based on cost function method. This paper performed an empirical analysis on the efficiency improvement and optimal scale taking the cost aspect in electricity industry into account. By expanding the cost structure framework, this paper proposes the analytical method regarding the needs of technology regulation and presents the empirical results which can be verified. Hence, this work can play a key role in decision-making of the national power development and regulatory policy. The empirical result indicates that the electricity industry in Korea has been in the state of economies of scale until 1980s, However, due to sustained growth of power generation, economies of scale declined and subsided after 1980s and then diseconomies of scale is shown recent years. The analysis on the effect of technology regulation shows the national large-scale base-load power plant development-oriented policy until so far contributed substantial cost effect to the electricity industry. The empirical result indicates that the reserve requirement as one of means of technology regulation policy did not contribute to the economies of scale but positive effect on the total factor productivity in Korea.

• 한국학교보건학회지
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• 제30권3호
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• pp.295-305
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• 2017

Purpose: This study was conducted to evaluate the effect of Mindfulness-based Emotion Management Training for adolescents immersed in self-harm behaviors. Methods: The participants were 61 middle school students located in Seoul. Thirty students were assigned to the Mindfulness-based Emotion Management Training (M-EMT) group and the other 31 students were assigned to the waitlist group. The students in the M-EMT group participated in a total of 12 sessions, twice a week, for 6 weeks. The modules of the program comprised of mindfulness for emotion, mindfulness for behavior/impulse, mindfulness for thought, and coping with self-harming behavior. The Distress Tolerance Scale, Deliberate Self-Harm Inventory, Cognitive Emotion Regulation Questionnaire, and Scale Suicidal Ideation were assessed at baseline and post-intervention. Results: Compared to the waitlist group, the intervention group exhibited a statistically significant improvement in distress tolerance and cognitive emotion regulation and a statistically significant reduction in self-harming behaviors and suicidal ideation. Conclusion: These results support the hypothesis that mindfulness-based emotional management training has a positive effect on reducing self-harming behaviors and enhancing distress tolerance and cognitive emotional regulation.

• 간호행정학회지
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• 제19권5호
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• pp.565-577
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• 2013

Purpose: This study was done to propose an improvement in the Nursing Fee Differentiation Policy to alleviate polarization of nursing staffing level among hospitals and to rectify the confusion of legally mandated standards between the Korean Medical Law and National Health Insurance Act. Methods: The policy regulation was reconstructed related to nurse staffing standards and nurse-to-patients ratios. Data on nurse staffing grades were obtained from database of the Health Insurance Review & Assessment Service (HIRA) for the third quarter of 2010 for 44 tertiary hospitals, 274 general hospitals, and 1,262 hospitals. A break-even analysis was used to estimate financial burden of the revised policy improvement proposal. An industrial engineering method was used to calculate Nurse-to-Patients ratios per shift. Results: Twelve tertiary hospitals were downgraded. 74 general hospitals and 102 hospitals were upgraded after application of the regulation. Finances for total hospitalization expenditures changed from -3.55% to +3.14%. Conclusion: The results indicate that the proposed policy would decrease polarization between tertiary hospitals and small hospitals, and would not put a major strain on the finances of the Korean National Health Insurance. Therefore, it is suggested that government stake-holders and many interest groups consider this policy proposal and build a consensus.